under
/usr/share
or
.local/share/applications/
create a desktop file like
[Desktop Entry]
Version=1.0
Type=Link
Name=Examples
Name[es]=Ejemplos
Name[fi]=Esimerkkejä
Name[fr]=Exemples
Comment=Example content for Ubuntu
Comment[es]=Contenido del ejemplo para Ubuntu
Comment[fi]=Esimerkkisisältöjä Ubuntulle
Comment[fr]=Contenu d'exemple pour Ubuntu
URL=file:///usr/share/example-content/
X-Ubuntu-Gettext-Domain=example-content
You can learn more about .desktop files here.